It is well known in manufacturing plants to connect a number of hydraulically operated machines to a common hydraulic fluid storage tank. For example, in an automotive stamping plant, a plurality of stamping presses will be connected to a common fluid storage tank because it is less costly and more convenient to maintain one common storage tank rather than a storage tank associated with each of the presses.
It is well known that the hydraulic fluid needs to be filtered because particulates can enter the fluid during operation of the presses. The particulates arise from the wear of the hydraulic seals and other moving parts that make up hydraulic cylinders, hydraulic valves, and other parts of the hydraulic piping system. The presence of the particulates within the hydraulic fluid creates an abrasive effect which will cause the generation of additional particulates by further wearing away at the seals, cylinders and valves.
It is well known to provide a hydraulic fluid filter at the outlet of the common fluid storage tank so that all of the fluid will pass through the filter, thus capturing the particulates and keeping the particulates out of the machinery. It is also known to periodically change the hydraulic fluid and clean the storage tanks.
It is also well known that the generation of particulates is reduced when the stamping presses receive proper periodic preventive maintenance, which may entail replacement of seals and valves and cylinders that may be deteriorating and thereby adding to the particulate problem.
It would be desirable to provide a method for the early diagnosis of machine faults of the type that create particulates so that the generation of particulates can be controlled by performing timely maintenance, rather than simply relying upon filters and sedimentation inside the tank to capture the particulates once they are generated.